Stihl BT 131, Инструкция по эксплуатации

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2.7 Diode Removal/ Replacement: -
1. Remove defective diode by clipping its leads as close as possible to diode body.
2. Bend the two remaining leads perpendicular y to the circuit board.
3. Observing diode polarity, wrap each lead of the new diode around the corresponding lead
on the circuit board.
4. Securely crimp each connection and solder it.
5. Inspect (on the circuit board copper side) the solder joints of the two "original" leads. If
they are not shiny, reheat them and if necessary, apply additional solder.
2.8 Fuse and Conventional Resistor Removal/ Replacement:
1. Clip each fuse or resistor lead at top of the circuit board hollows take.
2. Securely crimp the leads of replacement component around notch at stake top.
3. Solder the connections.
CAUTION: Maintain original spacing between the replaced component and adjacent
components and the circuit board to prevent excessive component temperatures.
2.9 Circuit Board Foil Repair
Excessive heat applied to the copper foil of any printed circuit board will weaken the
adhesive that bonds the foil to the circuit board causing the foil to separate from or "lift-off"
the board. The following guidelines and procedures should be followed whenever this
condition is encountered. At IC Connections to repair a
defective copper pattern at IC connections use the following procedure to install a jumper
wire on the copper pattern side of the circuit board. (Use this technique only on IC
connections).
1. Carefully remove the damaged copper pattern with a sharp knife. (Remove only as much
copper as absolutely necessary).
2. Carefully scratch away the solder resist and acrylic coating (if used) from the end of the
remaining copper pattern.
3. Bend a small "U" in one end of a small gauge jumper wire and carefully crimp it around
the IC pin. Solder the IC connection.
4. Route the jumper wire along the path of the out-away copper pattern and let it overlap
the previously scraped end of the good copper pattern. Solder the overlapped area and clip
off any excess jumper wire.
At Other Connections Use the following technique to repair the defective copper pattern at
connections other than IC Pins. This technique involves the installation of a jumper wire on
the component side of the circuit board.
1. Remove the defective copper pattern with a sharp knife. Remove at least 1/4 inch of
copper, to ensure that a hazardous condition will not exist if the jumper wire opens.
2. Trace along the copper pattern from both sides of the pattern break and locate the
nearest component that is directly connected to the affected copper pattern.
3. Connect insulated 20-gauge jumper wire from the lead of the nearest component on one
side of the pattern break to the lead of the nearest component on the other side. Carefully
crimp and solder the connections. CAUTION: Be sure the insulated jumper wire is dressed so
the it does not touch components or sharp edges.